Large mobile crane

ABSTRACT

The object of the invention is to reduce the amount of investment required for the usage-optimized configuration and installation of large cranes. This object is achieved by a large mobile crane having an undercarriage, a drive unit ( 16 ), a revolving superstructure ( 18 ), one or more control stations ( 17 ), at least two jibs ( 3 ), at least one counter-jib ( 4 ), at least two lifting arrangements ( 22 ) and counterweights arranged separately or on the basic structure, characterized in that the load-bearing parts of the crane ( 3, 4, 20 ) and the mobility-specific parts ( 5, 6, 7 ) are of modular design and can be supplemented by exchangeable and/or supplementary parts, wherein the structural units (modules) used essentially correspond, or are similar, to existing standard-crane components, and an increase in load-bearing capacity can be achieved by arranging a number of these in the large crane.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a U.S. national stage of International Application No.PCT/DE2006/001843, filed on 12 Oct. 2006. Priority is claimed on GermanApplication No. 10 2005 055 694.9, filed on 17 Nov. 2005, and GermanApplication No. 10 2006 015 307.3, filed on 29 Mar. 2006.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention pertains to a large mobile crane with an undercarriage, adrive unit, a superstructure, one or more control stations, at least twomain booms, at least one derrick boom, at least two lifting devices andcounterweights, either separate or mounted on the basic machine.

2. Description of the Related Art

Various solutions are known for lifting extremely heavy loads exceedingthe capacity of the various current mobile crane designs, large numbersof which are on the market.

It is possible, for example, with the use of the reliable mechanicalelements and materials already available for constructing cranes, tobuild a very large lattice-boom crawler crane whenever desired. As aresult of the necessary size of the individual components, however,considerable problems are encountered in the production of the castingsin particular, such as the base plates and cable drums as well as thehydraulic components. Although technological limits are reached in somecases, economic limits are reached in all cases, and all of the largecranes thus obtained would include individual pieces difficult to movefrom one work location to another. The large components presentsignificant problems with respect to transport and handling such as theability to be driven along ordinary roads and to pass under bridges. Analternative solution, namely, dividing the individual basic componentsinto smaller components, would lead to additional, relatively highcosts. Overall, a large machine of this type would be extremelyexpensive and, as experience has shown, would represent a commercialprototype.

Ring-lift cranes represent a different approach to the lifting of heavyloads. These usually have a large boom or a double-boom system (arrangedin parallel or in the shape of an “A”), which are supported on theground by way of a circular track. In the meantime, several patents havebeen granted for cranes of this type such as U.S. Pat. No. 4,103,783 andU.S. Pat. No. 4,196,816. The advantage of the ring-lift crane is thatmuch higher load moments can be reached than is possible with crawlercranes. The disadvantage is that ring-lift cranes cannot be moved with asuspended load, and even without a load they can be moved only withconsiderable effort. In addition, they can make use of only a fewcomponents of standard production cranes. They must therefore usually beassembled on site and thus block the progress of the construction workduring the tedious assembly and disassembly phases.

So-called derrick cranes are also known. Here a main boom is paired witha derrick boom, the two booms being mounted on the superstructure of amobile undercarriage or on a stationary foundation.

The extremely large dimensions of all these machines, as previouslymentioned, is disadvantageous, because they cause problems duringtransport and assembly/disassembly. They also suffer from poor lateralstability (especially serious in the case of loads with large surfaceareas exposed to the wind) because of the unfavorable relationshipbetween the large size of the machine and the short distance between thetracks of the crawler-type carriage

SUMMARY OF THE INVENTION

It is therefore the task of the present invention to eliminate thedisadvantages of the known solutions and thus to lower the investmentcost for the task-optimized design and installation of large cranes ofany desired type and with any desired set of properties.

According to the invention, wherein the components of the crane whichabsorb the load and the components which provide mobility are designedin modular fashion and can be replaced and supplemented with expansionparts, where the structural units (modules) used essentially correspondto, or resemble, existing standard crane components, and where multiplemodules can be combined to form a large crane with a greater workingload capacity.

The invention is based on the core idea of creating a mobile crane whichis variable, that is, a crane which can be built to suit a specificneed. This is accomplished essentially in that, as far as possible,components of existing standard production cranes are used in favorablecombinations with expansion parts in a wide variety of ways to achievelarge and very large crane configurations.

According to an especially advantageous embodiment, a crane of thederrick type has a double main boom arrangement and a double derrickboom arrangement. The two adjacent booms of a pair are connected to eachother preferably so that they are rigid with respect to moments. As aresult of this arrangement, the load capacity is significantly increasedwithout limiting the mobility of the basic machine.

Standard components are used as often as possible to build the variousconfigurations of the crane. This applies not only to the load-bearingcomponents but also to the parts which provide the mobility. Thus, forexample, through the modular design of the crawler-type carriage orcrawler carrier, the footprint can be easily and quickly increased, forwhich purpose standard components can also be used.

The ability to change the working load possibilities can be improvedeven more by simplifying the way in which the counterweight being usedcan be adapted to the load. In other words, it should be possiblewithout major effort to adapt the counterweight to heavier loads as wellas to reduce it so that the desired variability can be achieved. This isaccomplished by dividing the counterweight into a mobile component and astationary component. This separation is the object of the modularcounterweight carriage disclosed in WO 2007/056970.

So that the invention can be understood more clearly, it will beexplained in greater detail below on the basis of the drawings.

BRIEF DESCRIPTION OF THE DRAWING

FIGS. 1 and 2 show partial views of a double main boom-double derrickboom arrangement;

FIG. 3 shows the crawler-type carriage with the superstructure;

FIG. 4 shows the combination bottom block;

FIG. 5 shows a partial top view of the large crane;

FIG. 6 shows a schematic diagram of the undercarriage;

FIG. 7 shows a derrick crane according to the prior art;

FIG. 8 shows a corresponding partial top view;

FIG. 9 shows a schematic diagram of the undercarriage according to theprior art; and

FIG. 10 shows a schematic diagram of the inventive derrick crane.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The inventive large crane is a lattice-boom crawler crane and operatesaccording to the derrick crane principle; that is, the basic machine isdesigned without ballast as usual for this type of crane and supplieslittle or nothing to the stability moment of the crane.

FIGS. 7-9 show a derrick crane according to the prior art. In thefollowing description, the reference numbers will also pertain to thisknown design, because the components essential to an understanding ofthe invention can also be seen here.

The mechanical basis for the inventive large crane is thus formed bycomponents of existing standard production cranes and by the specialparts which are necessary to expand the basic crane into a large crane.

Several components of the inventive large crane are designed as modularcomponents.

In the following, ways in which the working load can be increased willbe considered.

Referring to FIG. 2, two symmetrically arranged booms 3 a, 3 b areconnected to each other by connecting elements 30 so that they arepreferably rigid with respect to moments. The derrick booms (superliftmasts 4 a, 4 b) shown in FIG. 1 and the combination bottom hook block 20a, 20 b, 21 (FIGS. 4 and 10) are designed in the same way, but here theyare free of moments.

Referring to FIGS. 3, 5, and 10, a crane superstructure 14 a, 14 b, 14c, 14 d of appropriately larger size and, according to the invention,made up of several components is used to support the boom components.The standard components used in the design of the crane include thedrive unit 16, the control station 17, a superstructure component 18,and the lifting device 22, several of which are provided. The reeving ofthe luffing gear 19 is necessary only to erect the double mast, andtherefore only one of them is sufficient.

The inventive combination of the booms makes it possible to lift loadswhich, in the case of short booms, are almost double that of the singleversion of the standard machine, and because of the greater lateralstability achieved with longer booms, the load can be double or evenmore than double that of a single standard machine.

The significantly increased working load capacity means that there isgreater load on the crawler undercarriage, which therefore must beredesigned appropriately. Components of standard cranes in combinationwith expansion parts are used here again according to the invention:Referring to FIG. 6, the crawler carriers 5 a, 5 b and 6 a, 6 b, whichare already of split design to reduce transport weight, are lengthenedby the insertion of an intermediate piece 10 a, 10 b. The middle section7 can continue to be used, and the distance between the tracks can beincreased or decreased by the insertion or elimination of additionalcomponents 8 a, 8 b and 9 a, 9 b.

Heavier loads can be handled by mounting a circular track (11) on theundercarriage, on which support rollers (12) connected to thesuperstructure ride. Because there is little or no moment in the loaddirection, only the lateral load moment resulting from the lateraldeformation and slanted position and the load need to be absorbed. As aresult, a more uniform load distribution is produced than in standardcommercial crawler cranes, and the crawler-type carriages originatingfrom the smaller standard cranes can thus withstand the greater load.The above-mentioned circular track 11 can be an integral part of thenecessary supplemental components (8 a, 8 b, 9 a, 9 b) or an independentload-bearing ring element, which is laid and fixed in place on thesupplemental components (8 a, 8 b, 9 a, 9 b).

Because the basic machine does not contribute to the stability moment, aheavier counterweight 13 must be mounted on the mast so that heavy loadscan be lifted. When the crane is turned or moved, this counterweightmust be carried along also. For this purpose, either crawler carriers(as in the solutions designed by Lampson) or counterweight carriages onwheels have been used so far. In addition to the procedure predominantlyused in engineering practice, namely, to build an appropriately largercounterweight carriage, there is also the possibility of using twocounterweight carriages in a tandem combination. Both of these arecomplicated and expensive single-purpose solutions.

In the present case, a combination solution is used consisting ofexisting movable components and existing or custom-built stationarycounterweight components. This separation is the object of the modularcounterweight carriage disclosed in WO 2007/056970.

In the construction of new industrial facilities and especially in themodernization of old facilities by the addition of high-rise units, thefeasibility of crane operation is determined predominantly by the timefactor, by the available space, and by the other conditions present atthe work site. The use of the inventive crane offers the followingadvantages:

(1) The crane can be assembled at any desired location, even in tightspaces, where it can lift the load from a different location, set itdown at any desired other location, and after use can be disassembled inany desired location, because operationally it can travel, rotate theload, and luff like a standard lattice-boom crawler crane, either withor without load.

(2) Because of the ability to combine standard machine components inmodular fashion with only a few expansion parts, several technical andcommercial advantages are created for the customer:

(a) Achievement of the greatest possible working load capacities andradii at modest additional investment cost. Only the expansion partsrequired to convert a standard machine to a large machine must be keptavailable;

(b) More effective utilization of the basic investment, because cranework can still be carried out with the standard machines at theiroriginal capacities (when the large crane is not needed);

(c) Lower transport costs, because the components of standard cranes areusually smaller than those suitable for large cranes;

(d) Only the large crane expansion parts must be transported from aconstruction site where standard machines are being used to the nextconstruction site, which means that large cranes of various capacitiescan be erected at various locations in a short time.

(e) Operationally relevant elements and processes known from standardcranes as well as maintenance and repair procedures can be retainedalmost without change.

(f) No special inventory of spare parts must be maintained; onlystandard spare parts.

What is claimed is:
 1. Large mobile crane comprising an undercarriage,wherein the undercarriage comprises a middle section between tracks,wherein a distance between the tracks can be increased or decreased bythe insertion or removal of expansion parts, said two tracks connectedon opposite sides of the undercarriage to permit movement of the largemobile crane, a drive unit, a superstructure, one or more controlstations, at least two main booms, at least one derrick boom, and atleast two lifting devices and counterweights, wherein saidcounterweights are either arranged separately of or mounted on theundercarriage, and wherein the large mobile crane further comprises acircular track mounted on the undercarriage, and support rollersattached to the superstructure, wherein the support rollers ride on thecircular track, and wherein the circular track is an independentload-bearing ring element being laid and fixed in place on the expansionparts.
 2. Large mobile crane according to claim 1, wherein the at leasttwo main booms are mounted symmetrically with respect to each other onthe superstructure, the booms being connected to each other byconnecting elements so that they are rigid with respect to moments. 3.Large mobile crane according to claim 1, wherein the counterweights arearranged both separately and on the undercarriage.
 4. Large mobile craneaccording to claim 1, wherein the main booms are paired with derrickbooms, which are connected to each other by connecting elements. 5.Large mobile crane according to claim 1, wherein the undercarriage is acrawler undercarriage and the two tracks are crawler tracks.
 6. Largemobile crane according to claim 1, wherein the at least two main boomsare arranged next to each other on the superstructure and are connectedto each other so that they are rigid with respect to moments, andwherein the main booms are paired with at least two derrick booms. 7.Large mobile crane according to claim 1, wherein the undercarriage hascrawler-type tracks arranged one behind the other or with an offset. 8.Large mobile crane according to claim 1, further comprising a pair ofbottom hook blocks which are combined with each other by means of aconnecting crosspiece.
 9. Large mobile crane according to claim 1,further comprising retaining rollers mounted on the superstructure. 10.Large mobile crane according claim 1, wherein the whole circular trackis completely arranged on the expansion parts.
 11. Large mobile craneaccording claim 1, wherein the circular track surrounds the middlesection, such that the circular track is spaced apart from the middlesection.